amit_upasani@hotmail.com wrote:
ywilfred wrote:
C doesn't contradict the passage.
We're told nothing on pluto vaporizes faster than methane, and slower than carbon monoxide.
That means there cannot be anything in between methane and carbon monoxide. The order Nitrogen->Carbon Monixide->Methane will not be changed.
In fact, A can be refuted to say there are other substances like frozen oxygen, and they could be higher in quantity. C cannot be challenged by this assumption even if you really had frozen oxygen, because we know that this frozen oxygen is not going to vaporize faster than methan and slower than carbon monoxide.
I disagree.
A few thing's I'd like to mention.
1. Ice vaporizes and produces gas. THe more vapor there is, the more concentration of that gas in the atmosphere. ( I think ywilfed is probably taking it to mean the other way i.e. more vaporization means less concentration in the atmosphere.)
I do get the point that more vaporization will result in a higher concentration of that gas in the atmosphere, and that's what I've been hitting at in this thread. We are told there is a direct relationship between vaporization of the frozen gas, and the proportion of that gas in the atmosphere. The faster the frozen gas vaporizes, the more of that gas we get. 2. So, from the passage, Nitrogen vaporizes faster than the other tow in the order Nitrogen > Carbon Mono > Methane, given that we start with similar quantities of each. If we start with 2 m^3 of Nitro vs. 100000 m^3 of methane, after a certain amount of time, the amount of Nitro gas in the atmosphere is going to be proportional to the 2m^3 even though it vaporizes much faster.
Choice C => There is no frozen substance on the surface of Pluto that vaporizes more readily than methane but less readily than carbon monoxide.
which contradicts #2 above. There actually are two substances that vaporize more readily than methane.
I see your point abt frozen oxygen, but with the given info, choice A is still the best.
Let's look at it another way. I'll employ the diagramming method I used earlier on, and insert the assumption in, then we'll see which one really plug the gap and hold the conclusion up. Also, we'll use the 'therefore' test to see if it fits in logically with the conclusion.
Here's the diagram of the passage.
1) Spectroscopic analysis revealed existence of frozen nitrogen, methane and carbon monoxide on surface of pluto
2) Such ice have tendency to vaporize, producing an atmosphere
3) Proportion of any gas in atmosphere depends directly on how readily corresponding ice vaporize
4) Therefore, Astronomers concluded that components of Pluto's atmosphere are nitrogen, Carbon monixide and methane in decreasing abundance.
Clearly, something is missing. The astronomers managed to conclude Nitrogen > CO > Methane in the atmosphere, just from the premise these ice vaporize to produce an atmosphere. We need something else, an assumption, to hold up the conclusion.
Let's try A. where I inserted it as premise 4 in the diagram.
1) Spectroscopic analysis revealed existence of frozen nitrogen, methane and carbon monoxide on surface of pluto
2) Such ice have tendency to vaporize, producing an atmosphere
3) Proportion of any gas in atmosphere depends directly on how readily corresponding ice vaporize
4) There is no more frozen nitrogen on the surface of Pluto than there is either frozen carbon monoxide or methane.
5) Therefore, Astronomers concluded that components of Pluto's atmosphere are nitrogen, Carbon monixide and methane in decreasing abundance.
Does it help understand why the astronomers made that conclusion ? It doesn't.
Now let's try C, where I inserted as premise 4 in the diagram.
1) Spectroscopic analysis revealed existence of frozen nitrogen, methane and carbon monoxide on surface of pluto
2) Such ice have tendency to vaporize, producing an atmosphere
3) Proportion of any gas in atmosphere depends directly on how readily corresponding ice vaporize
4) There is no frozen substance on the surface of Pluto that vaporizes more readily than methane but less readily than carbon monoxide
5) Therefore, Astronomers concluded that components of Pluto's atmosphere are nitrogen, Carbon monixide and methane in decreasing abundance.
Now this ties in more logically and the Astrnomers could conclude why it is Nitrogen > CO > Methan and not any other order.
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